The coming of the 21st Century will bring with it man's continuing settlement of frontiers in sea, sky and space first opened in the 20th Century. For this 21st Century colonization, new building strategies and techniques will be required to fabricate structures that will house, support and facilitate man and his activities. Because of the remoteness of these frontiers and the need for efficiency in performance and cost, the steel and concrete constructions that have characterized contemporary life in the past will no longer be suitable. Not only will the economics of transporting such conventional materials render them inappropriate for being carried into space, beneath the sea or even to sites on land for constructions ranging from space stations, to family dwellings, but also their bulk and awkwardness of handling will make them poor choices for the efficient and expansive structures contemplated for use in the 21st Century.
To this end, government and private sector engineers have undertaken joint programs to develop new and higher efficiency beam designs for use in building structures in these environments. Such efforts have placed particular emphasis on beam designs having low structural mass density and high geometrical stability over time. Further, these designs call for use of materials that can be cost effectively transported in bulk to remote construction cites, whether it be space, sea or earth, where they can be subsequently transformed into the beams and columns necessary to fabricate the desired structures.
More specifically, and as reported by T. J. Dunn, in NASA technical memorandum 58271, entitled Geodetic Beam Development Test published January 1986, workers at the National Aeronautics and Space Administration, in conjunction with private contractors developed a prototype geodetic beam of cylindrical open lattice form. In accordance with their design, the beam features an equilateral grid work of complimentary wound helical elements, further supported by multiple longitudinal elements, the multiple helical and longitudinal elements being bound by encapsulation placed at the respective cross points of the elements. While this construction as fashioned from wire made of a variety of materials such as aluminum and composites, showed some success, none the less, under loading tests, it exhibited failure points at the nodes where the wire elements crossed and were bonded to one another.
As reported, loading of the beams, particularly in compression, produced failure at the encapsulated cross points thus suggesting that regardless of the choice of wire element material and its dimensioning, the limiting factor for beam strength was node joint encapsulation. Further, and more fundamentally, in accordance with the NASA beam design, some form of bonding or encapsulation of the multiple wire elements was essential to beam integrity.